By Robert Bazell Chief science and health correspondent NBC News NBC News Detecting Alzheimer’s early, even before symptoms appear , is one of the big topics at the Alzheimer’s Association's International Conference now taking place in Paris. The subject has also been the focus of a number of scientific research papers in recent months. NBC's chief science and health correspondent Robert Bazell explains the benefits and limits of early detection, available treatments for dementia and whether people with a family history want to know their risks. Q: Is it possible to tell whether someone who has no symptoms now is going to get Alzheimer's in the future? A: The simple answer is no. It is not possible. Q: Then why is there so much discussion of the subject? A: Many research groups are developing methods that may soon help predict risk of Alzheimer’s disease. These include brain scans with radioactive markers that detect the level of amyloid, a protein in the brain assoc...